The present invention relates to a method and apparatus for the production of particulate matter of such nature and size and at such conditions of temperature and pressure as to either inhibit or stimulate precipitation in the atmosphere.
More particularly the present invention relates to a method and apparatus for the production of monodispersed aerosols of chemical materials effective as ice nuclei.
In the recent past a number of investigators, including applicant, have published articles which are considered pertinent to the field of the invention. Some of these are:
P. P. Wegener and A. A. Pouring, "Experiments on Condensation of Water Vapor by Homogeneous Nucleation in Nozzles," Physics of Fluids, Vol. 7, 1964, pp. 352-367.
E. R. Buckle and A. A. Pouring, "Effects of Seeding on the Condensation of Atmospheric Moisture in Nozzles," Nature, Vol. 208, No. 5008, pp. 367-369.
A. A. Pouring, "Thermal Choking and Condensation in Nozzles," Physics of Fluids, Vol. 8, No. 10, 1965, pp. 1802-1810.
A. A. Pouring, "Effects of Heterogeneous Nucleation of Water Vapor in Nozzles," Basic Engineering, December 1970, pp. 689-694.
N. Fukuta, "Advances in Organic Ice Nuclei Generator Technology," Proc. Internat. Conf. on Weather Modification, Canberra, Australia, 6-11 September, 1971, pp. 343-348.
N. Fukuta, "Advances in Organic Ice Nuclei Generator Technology," J. Rech. Atmos, "Desseus Memorial Issue," No. 1-2-3.
Paik, Y. N. Fukuta, and C. J. Todd, "A new Method of Generating Ice Nuclei Smoke Particles for Weather Modification," Proc. Third Conf. on Weather Modification, Rapid City, S. D., 25-29 June, 1972, pp. 30-32.
A. A. Pouring and E. R. Buckle, "The Kinetics of Evolution of Water Vapor Clusters in Air," U.S. Naval Academy E & W Report #3-74, December 1974 (in press).
"Investigation of Small Particles Produced by Gas-Dynamic Expansion of Vapor-Gas Mixtures," May 1974 (Senior Thesis), Midshipman 1/C Michael W. Moran, USN, advisor: A. A. Pouring.
According to the present invention supersonic flow phenomena in a converging-diverging nozzle or even a simple orifice with slightly supersonic flow are shown to be effective for production of ice nuclei, for example, for cloud seeding.